Muck Boots Arctic Adventure Rubber Kids' Snow Boot Synthetic Rubber sole Shaft measures approximately 12" from arch Boot opening measures approximately 13.5" around 4 mm neoprene provides comfort and flexibility, along with excellent waterproofing, shock absorption and heat retention properties; adjusts to the contours of your foot to resist blisters and chafing 100% waterproof kids' boots feature a high-grade extended rubber exterior for added toughness and extra coverage; 10-inch height offers excellent protection Soft fleece lining enhances comfort, provides superior warmth, and is durable enough for long cold treks; comfort rated from -20 F to 50 F (-30 C to 10 C) EVA footbed provides additional support and comfort Aggressive outsole helps prevent slips on slick surfaces; rear pull tab allows for easy on-off